<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
<script>
    //1.获取元素
    let bd = document.querySelector('body');
    //2.设置元素内容
    bd.innerHTML = '<p>牛客网是一个专注于程序员的学习和成长的专业平台。</p>'

</script>
    </body>
</html>